Principles of Operation

Special Tool(s)





Material

Principles of Operation
Cooling Fans

The cooling fans are controlled by four relays to provide three speeds. If DTC P1474, P1477 or P1479 are present, refer to Computer and Control Systems.

In HIGH speed, the cooling fans are wired parallel and the following relays are grounded by the PCM:
^ Fan braking relay.
^ Engine cooling fan relay.

In MEDIUM speed, the cooling fans are wired parallel through a resistor and the following relays are grounded by the PCM:
^ Fan braking relay.

In LOW speed, the cooling fans are wired in series and the following relays are grounded by the PCM:
^ Fan braking relay.
^ Engine cooling fan relay.
^ HEDF and EDF relay.